Regional trends in aquatic recovery from acidification in North America and Europe

Ecological issues related to N deposition to natural ecosystems: research needs

“…Aquatic ecosystems are not addressed in this analysis. Acidification of surface waters as a result of acidic deposition has been documented , and recovery, as sulfate deposition levels have decreased, has validated our understanding and modeling of this process (Stoddard et al, 1999). Eutrophication of estuaries as a result of high N loads, leading to hypoxic and anoxic zones, has been documented and is a serious concern (Paerl and Whitall, 1999).…”

Recovery of Acidified European Surface Waters

“…Since the mid-1980s, sulfur deposition has decreased by ~40% as a result of legislation implemented in Canada (Eastern Canada Acid Rain Programme; 36) and the United States (Clean Air Act Amendments; 37) and the 1991 Canada-U.S. Air Quality Agreement (38). Surface-water chemistry has begun to recover (11,(39)(40)(41)(42). Additional reductions in sulfur deposition may occur in the future.…”

Recovery of Soil Water, Groundwater, and Streamwater From Acidification at the Swedish Integrated Monitoring Catchments

“…In the most heavily polluted southwestern part of Sweden, this corresponds to a reduction from 9 to 3 kg S ha -1 year -1 and from 10 to 6 kg N ha -1 year -1 (sea salt corrected, Bertills et al 2007). As a result, it could be expected that ecosystems that had been acidified by earlier and chronic S deposition loading would now be showing signs of recovery, and indeed surface waters throughout the northern hemisphere are doing so (Evans et al 2001;Skjelkvåle et al 2005;Stoddard et al 1999).…”